The present invention relates to devices for packaging selected items More particularly, the present invention relates to devices for continuously packaging selected items in a controlled atmosphere enclosure.
It is known to package items, specifically selected food items, in packages having a controlled atmosphere. Normally, this controlled atmosphere is a low oxygen atmosphere, with the oxygen replaced by an inert gas. Such controlled atmosphere enclosures or packages are necessary to insure adequate shelf life for many of the selected food items. By eliminating the majority of oxygen from the package, the shelf life of the food item is greatly increased.
Normally, the controlled atmosphere within the package is obtained in one of two conventional ways. First, machines have been adapted to simply introduce the inert gas into the stationary package, with the inert gas partially displacing the ambient oxygen in the package. After the inert gas is introduced, the package is sealed. This method has generally proved unsatisfactory because it is extremely difficult to lower the oxygen content within the package to a desirable level, and it is extremely slow.
The second method of achieving a controlled atmosphere in the package has been by utilizing a vacuum in combination with a gas flush machine. In such a conventional machine, the package is placed in a vacuum chamber which creates a vacuum in the package. After the vacuum has been created in the package, the selected gas is introduced into the package, and the package is then sealed. Some conventional vacuum gas flush devices also introduce a vacuum through one side of the package, while the selected gas is introduced through the opposite side of the package. However, all of the conventional vacuum gas flush devices utilize a vacuum chamber to perform these functions. In all of these devices, it is necessary for the package to stop for a period of time in the vacuum chamber. Thus, none of the conventional vacuum gas flush devices is capable of continuously conveying a series of packages, with the controlled atmosphere introduced into the package and the package sealed without stopping any of the packages. Production using conventional devices is slow an therefore expensive.
One object of the present invention is to provide a controlled atmosphere packaging device that is capable of creating a controlled atmosphere within a package, and is also capable of sealing the package to maintain that selected controlled atmosphere.
Another object of the present invention is to provide a controlled atmosphere packaging device that is capable of creating a controlled atmosphere within the package without the use of a vacuum chamber to enclose the package for a period of time.
Yet another object of the present invention is to provide a controlled atmosphere packaging device that is capable of packaging selected items with a controlled atmosphere within the package in a continuous manner.
According to the present invention, an apparatus for packaging an item in a controlled atmosphere enclosure is provided. The apparatus comprises means for continuously conveying a series of containers along a defined path. The path has sequentially oriented first and second portions, and defines a first side border and an opposite second side border. The apparatus also has means for introducing a covering material move the path of containers such that a space is created between the containers and the covering material. Means disposed substantially adjacent the first border are provided for applying a vacuum to the space only in the first portion of the path. Means disposed substantially adjacent the second border are provided for continuously introducing a selected gas into the space in both the first portion and in the second portion of the path. The apparatus also has means for mating and sealing the containers with a corresponding section of the covering material in the second portion of the path to form a controlled atmosphere environment enclosure.
One feature of the foregoing structure is that the apparatus has means for continuously conveying a series of containers along the path. One advantage of this feature is that it is not necessary to stop the package in the machine in order to introduce the controlled atmosphere into the package.
Another feature of the foregoing structure is that the covering material that is used to cover the containers is oriented such that a space is created between the containers and the covering material. One advantage of this feature is that the area in which the vacuum is applied and the gas is introduced is defined by the moving containers and moving covering material. This eliminates the necessity for any additional vacuum chamber into which the vacuum is applied.
In preferred embodiments of the present invention, the path includes a first end configured to receive the series of containers, and the apparatus further includes second gas supply means disposed substantially adjacent the first end of the path and extending between the first and second side borders. The second gas supply means is configured to introduce gas into the first end of the path so that the gas is able to communicate with an interior region of each of the containers as the containers enter the path through the first end.
One feature of the foregoing structure is that an additional gas supply means is disposed across the first end of the path for introducing the selected gas into each container as it enters the path. One advantage of this feature is that the selected gas is first introduced directly into each container which aids in initially eliminating a substantial portion of the oxygen content of the container to enhance the oxygen evacuating capability of the device.
Applicant's device is thus capable of packaging a selected item in a container with a controlled atmosphere captured within the container. Applicant's apparatus is capable of continuously conveying the containers along a selected path such that the packaging process is accomplished at a commercially acceptable rate of production. During a substantial portion of the path, a vacuum is applied to one side of a space defined between the containers and a covering material, and a selected gas is introduced into the other side of the space. In a second portion of the path, only the selected gas is introduced into the space, and consequently into the container. This limitation of the application of the vacuum prevents the possible introduction of any unwanted ambient atmosphere as the container is being mated to the covering material, and consequently increases the capability of the apparatus to introduce a controlled, defined atmosphere into each container.
Additional objects, features, and advantages of the invention will be apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.